During for example motor cross it is sometimes desirable to have a lower pressure in the tyres than what is normal for driving on roads. This puts other demands on rims and tyres. During low pressures the tyre becomes more sensitive for hits and other external impacts. On the one hand the low pressure means that the tyre is less attached to the rim, because normally it is the air pressure that presses the tyre beads against the rim flanges. Moreover the low pressure leads to that the tyre may be squeezed and sometimes punctured between the rim flange and the surface. A punctured tyre may also lead to the risk of the tyre being wrought off the rim, whereby the motorcycle is not drivable any more. For safety and competition reasons it might for some situations be necessary to wait with changing of tyres and to continue the driving despite a punctured tyre. It would therefore be desirable to have a device that enables loads on the tyre even if the tyre has been punctured.
EP 0 695 651 discloses a device for locking a tyre to a rim. It comprises a tubular member that is placed inside the tyre having a diameter such that it is in the vicinity of the beads. It is further arranged with a valve protruding through a hole in the rim, for inflating the tubular member. When this is done, the tubular member will press against the beads, which in turn press against the flanges of the rim.
The drawback with the device according to EP 0 695 651 is that the rim needs two holes for valves, one for the tubular member and the other for the tyre. Further, an airtight band is required, abutting the inner surface of the rim for preventing air from escaping through the rim. In all, the device is difficult to attach to a rim, to arrange the tubular member in the right position and to inflate both the tyre and the locking member.
Document DE2806325 discloses a method according to the preamble of claim 1.